AB0801 NEW DIAGNOSTIC TOOL IN BEHCET’S DISEASE
Authors: C. Soliz, J. A. Brigante, J. Rebak, L. L. Holguín Arias, L. Sorrentino, G. Gómez, A. Hamaui, D. Dubinsky
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Behcet's disease (BD) is characterized by oral, genital, and gastrointestinal manifestations. The pathergy test is used as a diagnostic tool, but this is not specific to BD, since it can be found in other diseases and can equally be negative even having the disease. Another characteristic of BD is the vascular compromise, predominantly venous. In a study, the measurement of the thickness of the common femoral vein (CVF) proved to be a diagnostic test with sensitivity and specificity greater than 80% for the cut-off value of 0.5 mm. <h3>Objectives</h3> To evaluate the diagnostic performance of the thickness of the posterior wall of the common femoral vein, measured by Doppler ultrasound for the diagnosis of Behcet's disease. <h3>Methods</h3> A multicenter pilot study was carried out to evaluate a diagnostic test. Data were collected by reviewing medical records collected from patients who met the 2014 International Criteria for Behcet's Disease (ICBD), and healthy controls. Venous Doppler ultrasound of the lower limbs was performed in both groups using an ultrasound evaluation protocol, considering posterior wall thickness of the CFV ≥ 0.5 mm as positive. <h3>Results</h3> 19 patients with EB and 19 healthy controls were included. The mean age of patients with DB was 47 (SD 12.6), and the median age of healthy patients was 41 years (IQR 36.5-48.5). 57.89% were mestizo in the BD group and 68.42% in the control group. The median delay in diagnosis was 19 months (IQR 11-36). The presence of HLA B51 was 63.15% and the positive pathergy test was found in 31.57%. At the time of the study, 42.10% had disease activity and a mean of 8.8 years of disease. (Table 1) The ultrasound was positive in 89.4% of patients with BD and 10.5% in the healthy group, observing a sensitivity of 94.1% and a specificity of 94.7%, with an area under the curve 0.89 (p &lt; 0.0001), PPV 94.1% and NPV 94.7%. (Fig. 1) We observe a post-test probability of 0.059. The test presents LR + 17.8 (95%CI 2.5-127) and LR - 0.06 (95%CI 0.008-0.4) <h3>Conclusion</h3> The diagnosis of Behcet's disease is difficult because it is based mainly on clinical manifestations, so this ultrasound test has a good capacity to be used as part of the diagnosis in patients with clinical suspicion, since it has a good sensitivity and specificity profile, low cost and simplicity. <h3>References</h3> [1]Jennette JC, Falk RJ, Bacon PA et al. 2012 revised International Chapel Hill Consensus conference nomenclature of vasculitides. Arthritis Rheum 2013;65: 1–11. [2]Calamia KT, Schirmer M, Melikoglu M. Major vessel involvement in Bechet's disease: an update. Curr Opin Rheumatol 2011; 23:24–31. [3]Alibaz-Oner F, Ergelen R, Yildiz Y, Aldag M, Yazici A, Cefle A, Koç E, Artim Esen B, Mumcu G, Ergun T, Direskeneli H. Femoral vein wall thickness measurement: A new diagnostic tool for Behçet's disease. Rheumatology (Oxford). 2021 Jan 5;60(1):288-296. doi: 10.1093/rheumatology/keaa264. PMID: 32756998. [4]Tezcan D, Özer H, Gülcemal S, Hakbilen S, Durmaz MS, Batur A, Yilmaz S. Diagnostic Performance of Lower Extremity Venous Wall Thickness and Laboratory Findings in the Diagnosis of the Behçet Disease. J Clin Rheumatol. 2022 Mar 1;28(2):e521-e527. doi: 10.1097/RHU.0000000000001788. PMID: 34538847. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> None Declared.